diff --git a/smithy-typescript-codegen/src/main/java/software/amazon/smithy/typescript/codegen/StructuredMemberWriter.java b/smithy-typescript-codegen/src/main/java/software/amazon/smithy/typescript/codegen/StructuredMemberWriter.java
index 9edab34d0a1..cbfbece087c 100644
--- a/smithy-typescript-codegen/src/main/java/software/amazon/smithy/typescript/codegen/StructuredMemberWriter.java
+++ b/smithy-typescript-codegen/src/main/java/software/amazon/smithy/typescript/codegen/StructuredMemberWriter.java
@@ -409,8 +409,16 @@ void writeValidateMethodContents(TypeScriptWriter writer, String param) {
                     // the object
                     optionalSuffix = "?.toString()";
                 }
-                writer.write("...getMemberValidator($1S).validate($2L.$1L$4L, `$${path}/$3L`),",
+                Shape memberTarget = model.expectShape(member.getTarget());
+                if (memberTarget.isUnionShape() && memberTarget.hasTrait(StreamingTrait.class)) {
+                    // todo: validating event streams in unsupported.
+                    writer.write("// unsupported event stream validation");
+                    writer.write("// ...getMemberValidator($1S).validate($2L.$1L$4L, `$${path}/$3L`),",
                         getSanitizedMemberName(member), param, member.getMemberName(), optionalSuffix);
+                } else {
+                    writer.write("...getMemberValidator($1S).validate($2L.$1L$4L, `$${path}/$3L`),",
+                        getSanitizedMemberName(member), param, member.getMemberName(), optionalSuffix);
+                }
             }
         });
     }
@@ -458,7 +466,14 @@ private void writeMemberValidator(TypeScriptWriter writer,
                     getValidatorValueType(shape),
                     () -> {
                         writeShapeValidator(writer, shape, constraintTraits, ",");
-                        writer.write("$T.validate", symbolProvider.toSymbol(shape));
+                        if (!shape.hasTrait(ErrorTrait.class)) {
+                            writer.write("$T.validate", symbolProvider.toSymbol(shape));
+                        } else {
+                            // todo: unsupported
+                            // Error classes have no static validator.
+                            writer.write("""
+                                () => [/*Error validator unsupported*/]""");
+                        }
                     });
         } else if (shape.isListShape() || shape.isSetShape()) {
             writer.addImport("CompositeCollectionValidator",
diff --git a/smithy-typescript-codegen/src/main/java/software/amazon/smithy/typescript/codegen/TypeScriptDependency.java b/smithy-typescript-codegen/src/main/java/software/amazon/smithy/typescript/codegen/TypeScriptDependency.java
index b92c872119b..6331ad7e9a7 100644
--- a/smithy-typescript-codegen/src/main/java/software/amazon/smithy/typescript/codegen/TypeScriptDependency.java
+++ b/smithy-typescript-codegen/src/main/java/software/amazon/smithy/typescript/codegen/TypeScriptDependency.java
@@ -103,6 +103,7 @@ public enum TypeScriptDependency implements Dependency {
         false),
     AWS_SDK_EVENTSTREAM_SERDE_NODE("dependencies", "@smithy/eventstream-serde-node", false),
     AWS_SDK_EVENTSTREAM_SERDE_BROWSER("dependencies", "@smithy/eventstream-serde-browser", false),
+    AWS_SDK_EVENTSTREAM_CODEC("dependencies", "@smithy/eventstream-codec", false),
 
     // Conditionally added if a requestCompression shape is found on any model operation.
     MIDDLEWARE_COMPRESSION("dependencies", "@smithy/middleware-compression", false),
diff --git a/smithy-typescript-codegen/src/main/java/software/amazon/smithy/typescript/codegen/integration/EventStreamGenerator.java b/smithy-typescript-codegen/src/main/java/software/amazon/smithy/typescript/codegen/integration/EventStreamGenerator.java
index 587a7c76e22..2ab54d5427d 100644
--- a/smithy-typescript-codegen/src/main/java/software/amazon/smithy/typescript/codegen/integration/EventStreamGenerator.java
+++ b/smithy-typescript-codegen/src/main/java/software/amazon/smithy/typescript/codegen/integration/EventStreamGenerator.java
@@ -334,8 +334,16 @@ private void writeEventHeaders(GenerationContext context, StructureShape event)
             String memberName = headerMember.getMemberName();
             Shape target = model.expectShape(headerMember.getTarget());
             writer.openBlock("if (input.$L != null) {", "}", memberName, () -> {
-                writer.write("headers[$1S] = { type: $2S, value: input.$1L }", memberName,
+                if (target.isLongShape()) {
+                    writer.addImport("Int64", "__Int64", TypeScriptDependency.AWS_SDK_EVENTSTREAM_CODEC);
+                    writer.write("headers[$1S] = { type: $2S, value: __Int64.fromNumber(input.$1L) }",
+                        memberName,
+                        getEventHeaderType(target)
+                    );
+                } else {
+                    writer.write("headers[$1S] = { type: $2S, value: input.$1L }", memberName,
                         getEventHeaderType(target));
+                }
             });
         }
     }
diff --git a/smithy-typescript-codegen/src/main/java/software/amazon/smithy/typescript/codegen/integration/HttpBindingProtocolGenerator.java b/smithy-typescript-codegen/src/main/java/software/amazon/smithy/typescript/codegen/integration/HttpBindingProtocolGenerator.java
index edf9506d025..4a9b2fb75cc 100644
--- a/smithy-typescript-codegen/src/main/java/software/amazon/smithy/typescript/codegen/integration/HttpBindingProtocolGenerator.java
+++ b/smithy-typescript-codegen/src/main/java/software/amazon/smithy/typescript/codegen/integration/HttpBindingProtocolGenerator.java
@@ -559,7 +559,7 @@ private void generateOperationResponseSerializer(
                 + "  input: $T,\n"
                 + "  ctx: ServerSerdeContext\n"
                 + "): Promise<$T> => {", "}", methodName, outputType, responseType, () -> {
-            writeEmptyEndpoint(context);
+            writeEmptyEndpoint(context, operation);
             writeOperationStatusCode(context, operation, bindingIndex, trait);
             writeResponseHeaders(context, operation, bindingIndex,
                     () -> writeDefaultOutputHeaders(context, operation));
@@ -646,14 +646,36 @@ private void generateErrorSerializationImplementation(GenerationContext context,
     }
 
     private void writeEmptyEndpoint(GenerationContext context) {
-        context.getWriter().write("const context: __SerdeContext = {\n"
-                + "  ...ctx,\n"
-                + "  endpoint: () => Promise.resolve({\n"
-                + "    protocol: '',\n"
-                + "    hostname: '',\n"
-                + "    path: '',\n"
-                + "  }),\n"
-                + "}");
+        context.getWriter().write("""
+            const context: __SerdeContext = {
+              ...ctx,
+              endpoint: () => Promise.resolve({
+                protocol: '',
+                hostname: '',
+                path: '',
+              }),
+            };"""
+        );
+    }
+
+    private void writeEmptyEndpoint(GenerationContext context, OperationShape operation) {
+        String contextType = "__SerdeContext";
+        boolean hasEventStreamResponse = EventStreamGenerator.hasEventStreamOutput(context, operation);
+        if (hasEventStreamResponse) {
+            // todo: unsupported SSDK feature.
+            contextType += "& any /*event stream context unsupported in ssdk*/";
+        }
+        context.getWriter().write("""
+            const context: $L = {
+              ...ctx,
+              endpoint: () => Promise.resolve({
+                protocol: '',
+                hostname: '',
+                path: '',
+              }),
+            };""",
+            contextType
+        );
     }
 
     private void generateOperationRequestSerializer(
@@ -2205,10 +2227,18 @@ private void generateErrorDeserializer(GenerationContext context, StructureShape
                 Shape target = model.expectShape(binding.getMember().getTarget());
                 deserializingDocumentShapes.add(target);
             });
-            writer.openBlock("const exception = new $T({", "});", errorSymbol, () -> {
-                writer.write("$$metadata: deserializeMetadata($L),", outputName);
-                writer.write("...contents");
-            });
+            // todo: unsupported ssdk feature.
+            String serverSdkInfix = context.getSettings().generateServerSdk()
+                ? ": any /* $metadata unsupported on ssdk error */"
+                : "";
+            writer.openBlock("const exception$L = new $T({", "});",
+                serverSdkInfix,
+                errorSymbol,
+                () -> {
+                    writer.write("$$metadata: deserializeMetadata($L),", outputName);
+                    writer.write("...contents");
+                }
+            );
             String errorLocation = this.getErrorBodyLocation(context, outputName + ".body");
             writer.addImport("decorateServiceException", "__decorateServiceException",
                     TypeScriptDependency.AWS_SMITHY_CLIENT);